Failed attempt to boot a (non-debug) head -r339076 on an old PowerMac G5 "Quad Core" (built via devel/powerpc64-gcc): Waking up CPU 1

[Mark Millard]

On 2018-Oct-9, at 2:28 PM, Mark Millard <marklmi at yahoo.com> wrote:

> On 2018-Oct-9, at 1:40 PM, Michael Tuexen <tuexen at fh-muenster.de> wrote:
> 
>>> On 9. Oct 2018, at 22:35, Mark Millard <marklmi at yahoo.com> wrote:
>>> 
>>> [Reverting head -r334498 in my head -r339076 context was enough to get
>>> the G5 so-called "Quad Core" to boot just fine as a variant of
>>> -r339076 .]
>>> 
>>> On 2018-Oct-9, at 12:54 PM, Mark Millard <marklmi at yahoo.com> wrote:
>>> 
>>>> On 2018-Oct-9, at 8:20 AM, Mark Millard <marklmi at yahoo.com> wrote:
>>>> 
>>>>> [The stable/head mix seems to be a wrong idea: 11.2 gets past
>>>>> the SMP: messages just fine on the so-called G5 "Quad Core".]
>>>>> 
>>>>> On 2018-Oct-8, at 5:14 PM, Mark Millard <marklmi at yahoo.com> wrote:
>>>>> 
>>>>>> On 2018-Oct-8, at 1:27 PM, Justin Hibbits <chmeeedalf at gmail.com> wrote:
>>>>>> 
>>>>>>>> . . .
>>>>>>> 
>>>>>>> It would be helpful to know the last known-good SVN revision, both for
>>>>>>> Head and 11.x, as well as the oldest failing one.  Since my G5 bit the
>>>>>>> dust, I can't check locally.
>>>>>> 
>>>>> . . .
>>>> 
>>>> There are examples of head's kernels that sometimes
>>>> fail to get to the "SMP:" messages and sometimes work
>>>> for getting there (and beyond). So:
>>>> 
>>>> My reporting any example failure is a solid indicator
>>>> of the "does not reach "SMP:" problem in that build.
>>>> (All tries reached the waking message on at least cpu
>>>> 1.)
>>>> 
>>>> My reporting "worked" for a revision might be a
>>>> misclassification. (This makes for a messier
>>>> "binary-like search".)
>>>> 
>>>> That said, the summary of the later detail is:
>>>> 
>>>> head -r334494 kernel worked
>>>> head -r334528 kernel failed
>>>> 
>>>> (There is nothing between those for:
>>>> 
>>>> https://artifact.ci.freebsd.org/snapshot/head/r*/powerpc/powerpc64/kernel.txz
>>>> 
>>>> so getting a smaller range requires builds.
>>>> I've not attempted that.)
>>>> 
>>>> The only machine-dependent powerpc64 change between
>>>> those 2 that I see is:
>>>> 
>>>> Author: jhibbits
>>>> Date: Fri Jun  1 21:37:20 2018
>>>> New Revision: 334498
>>>> URL: 
>>>> https://svnweb.freebsd.org/changeset/base/334498
>>>> 
>>>> 
>>>> Log:
>>>> Increase powerpc64 KVA from ~7.25GB to 32GB
>>>> . . .
>>>> 
>>>> . . .
>>> 
>>> In my -r339076 build context I reverted -r334498, did a
>>> buildkernel, installed it, and rebooted into -r339076.
>>> 
>>> The result booted just fine.
>>> 
>>> It does appear that, for head, -r334498 makes the difference
>>> for some reason.
>> Are you saying that head with reverting r334498 runs stable with SMP?
>> 
> 
> So far no problems. I'll later be doing more extensive activity, such
> as buildworld buildkernel and poudriere-based port builds. So the
> quality of evidence will improve and I'll report on how it went.
> 

So far I've done -j4 buildworld buildkernel twice, both have
worked fine. The examples were:

Once via using devel/powerpc64-gcc and devel/powerpc64-binutils (or
devel/binutils).

Once via using system-clang and devel/powerpc64-binutils (or
devel/binutils), not that one would normally want to install and
try to boot and use the result.

It will be a while before I get around to starting poudriere-devel
based port builds.


Note: Since 2014 or so when I started FreeBSD activity on old
PowerMac's (including some with multiple sockets from the start),
I've never before disabled smp, even temporarily.


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)